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US 11,860,406 B2Granted
Optical fiber
AssigneeFujikura Ltd.
InventorRyo Maruyama
Life of this patent
Estimating the term…
Abstract
An optical fiber includes a glass portion, a primary coating layer, and a secondary coating layer. In the optical fiber, a value of microbend loss characteristic factor FμBL_GΔβ is 6.1 ([GPa−1·μm−2.5/rad8]·10−12) or less when represented by FμBL_GΔβ=FμBL_G×FμBL_Δβ, where FμBL_G is geometry microbend loss characteristic and FμBL_Δβ is optical microbend loss characteristic.
Claims21
An optical fiber comprising:
- a glass portion including a core;
- a clad surrounding the core;
- a primary coating layer covering the clad;
- and
- a secondary coating layer covering the primary coating layer, wherein
- a value of microbend loss characteristic factor FμBL_GΔβ ([GPa−1·μm−2.5/rad8]·10−12) is 6.1 ([GPa−1·μm−2.5/rad8]·10−12) or less when represented by FμBL_GΔβ=FμBL_G×FμBL_Δβ,
- wherein geometry microbend loss characteristic FμBL_G ([GPa−1·μm−2.5/rad8]·10−12) of the optical fiber is represented by
- F
- μ
-
- BL
-
- _
-
- G
- =
- K
- s
- 2
- H
- f
- 2
- ×
- D
- 0
- 0.375
- ×
- H
- 0
- 0.625
- K
- s
- =
- E
- p
-
- d
- f
- t
- p
- ,
-
- H
- f
- =
- π
- 4
-
- E
- g
-
- (
- d
- f
- 2
- )
- 4
- ,
-
- D
- 0
- =
- E
- p
- +
- (
- t
- s
- R
- s
- )
- 3
-
- E
- s
- ,
-
- H
- 0
- =
- π
- 4
-
- E
- s
-
- (
- R
- s
- 4
- -
- R
- p
- 4
- )
- ,
- where
- κs (MPa) is a spring coefficient of the primary coating layer,
- Hf (MPa·μm4) is a bending rigidity of the glass portion,
- D0 (MPa) is a deformation resistance of the secondary coating layer,
- H0 (MPa·μm4) is a bending rigidity of the secondary coating layer,
- Eg (GPa) is a Young's modulus of the glass portion,
- Ep (MPa) is a Young's modulus of the primary coating layer,
- Es (MPa) is a Young's modulus of the secondary coating layer,
- df (μm) is an outside diameter of the glass portion,
- Rp (μm) is a radius of an outer peripheral surface of the primary coating layer,
- Rs (μm) is a radius of an outer peripheral surface of the secondary coating layer,
- tp (μm) is a thickness of the primary coating layer, and
- ts (μm) is a thickness of the secondary coating layer, and
- wherein optical microbend loss characteristic FμBL_Δβ (1/(rad/μm)8) of the optical fiber is represented by
- F
- μ
-
- BL
-
- _Δβ
- =
- 1
- (
- Δβ
- )
- 8
- ,
- where Δβ (rad/m) is a propagation constant difference between propagation constant of a waveguide mode propagating through the optical fiber and propagation constant of a radiation mode.
121 more elements
Dependencies are inferred from the claim text.